Indications for the Implantation of Antitachycardia Devices (ICD’s) and Cardiac Resynchronization Devices (CRT Devices):

Emphasis on Judicious Use

Presented by: Electrophysiology Advisory Group

Michigan Chapter of the American College of Cardiology

The Electrophysiology Advisory Group, created by the Michigan Chapter of the American College of Cardiology (ACC), evaluated published literature and ICD implantation guidelines and, in 2004, created a consensus document. These guidelines were made available to cardiologists and hospitals in the State of Michigan and to Blue Cross Blue Shield of Michigan who jointly sponsored their development. They have been available on the Chapter’s Web-site. They mirrored, for the most part, ACC/AHA published guidelines.

The Center for Medicare Services (CMS) had also issued policy regarding reimbursement, for prophylactic ICD’s in particular, that was somewhat at odds with published literature. Further clinical trials have been since been published, analyzed, and with input from our various societies, CMS has issued new, expanded guidelines. A national ICD registry is now in place and institutions are required to track utilization and outcomes for patients in whom prophylactic ICD’s are implanted. We have evaluated those criteria and the new studies and have updated the guidelines as follows. Also included now is a section on the indications for CRT devices.

To be consistent with the ACC/AHA methodology, each of the following indications is assigned to Class I and II (A and B). Commentary that accompanies these indications reflects discussions between members at the time of our recent meeting (and feedback that followed reviews of the draft document). One of the requests to the advisory group was to highlight situations where one might consider the therapy inappropriate, hence the caveats listed.

As is the case with all guidelines, they are not expected to cover every clinical circumstance where the treatment might be considered. Moreover, individual patient’s circumstances may not always necessarily fit into the specific scenarios included in such guidelines.

We have divided the indications for ICD into primary (i.e., prophylactic) and secondary (i.e., after an event). The major published studies, which have led to the bulk of the guidance for both ICD’s and CRT devices, are appended.

While there is still some debate, it is the opinion of the Michigan Chapter’s Electrophysiology Advisory Panel that experience with the implantation of pacemakers is by itself insufficient to provide competence for the implantation of ICD’s. The scrutiny of patient indications; the selection of appropriate ICD devices; the appropriate programming and subsequent troubleshooting of ICD’s is best done by cardiologists with specific training in these aspects of device therapy. The Heart Rhythm Society has published a consensus document regarding such qualifications.

ICD IMPLANTATION

A. As SECONDARY Prevention

  1. Survivor of Sudden Cardiac Death (SCD) not due to definitively reversible causes and due to ventricular fibrillation or ventricular tachycardia (VT) (Class I)
  2. Spontaneous sustained VT (other than idiopathic type) (Class I)
  3. Syncope of unknown mechanism with electrophysiology study (EPS) showing inducible, sustained VT (Class I)
  4. Syncope of unknown mechanism in a patient with non-ischemic, dilated cardiomyopathy (Class IIB)
  5. Syncope of unknown mechanism in association with Brugada Syndrome or other high-risk channelopathy (e.g., Long QT syndrome) (Class IIB)
  6. Syncope or other severe symptoms due to VT in patients awaiting transplantation (Class IIB).
  7. Syncope of unknown cause in patient with hypertrophic cardiomyopathy (Class IIB)

Caveats:

  • VF or sustained VT within the first 48 hours of an acute ST-elevation myocardial infarction (MI) is considered in most cases to have been due to a reversible cause. However, monomorphic VT may imply fixed arrhythmogenic substrate if there is a history of prior MI.
  • VF or sustained VT in a patient with an acute coronary syndrome with completely normal LV function who subsequently is shown to have severe coronary disease is usually best treated with revascularization if clinically feasible
  • ICD therapy is inappropriate for patients with poor prognosis either on the basis of primary cardiovascular condition or because of co-morbidities

B. As PRIMARY Prevention

  1. Patient with following risk factor profile (Class IIA):
  2. LVEF 0.35
  3. Prior MI
  4. Ischemic cardiomyopathy

Caveats:

  • This combines data from MADIT II and SCDHeFT studies.
  • Assessment of indication should be made at least 1 month after MI and at least 3 months after revascularization.
  • Heart failure: Needn’t be present if LVEF  0.30. Class II or III heart failure or inducible, sustained VT or VF is required for 0.31 to 0.35. Class IV precludes use of this set of criteria.
  • The presence of coronary artery disease (CAD) and global hypokinesis without discrete MI was not an inclusion criterion in the MADIT II study
  • LV dysfunction with incidental, non-obstructive CAD should not render the patient a diagnosis of an ischemic cardiomyopathy
  • ICD therapy is inappropriate for patients with poor prognosis either on the basis of primary cardiovascular condition or because of co-morbidities
  1. Patient with following risk factor profile (Class IIB):
  2. LVEF > 0.30 and 0.40
  3. Prior MI
  4. Non-sustained VT
  5. Inducible, sustained VT or VF at EPS

Caveats:

  • This criteria is defined by the MUSTT study
  • Assessment made of indication should be made at least 3 days after MI and at least three days after CABG
  • MUSTT patients with inducible VF were randomized to therapy only if induced with double or single extrastimuli
  • ICD therapy is inappropriate for patients with poor prognosis either on the basis of primary cardiovascular condition or because of co-morbidities
  1. Patients with Non-Ischemic Cardiomyopathy
  2. LVEF  0.35
  3. Diagnosis present for > 9 months (CMS requirement)
  4. Class II or III heart failure
  5. This criteria is defined by SCDHeFT study
  6. The diagnosis duration is to guard against implantation of a prophylactic ICD in a

patient whose LV dysfunction may be reversible

  • The nine months exceeds the duration used in SCDHeFT and CMS may reconsider this criterion
  1. Patient with the following risk factor profiles:
  2. Hypertrophic cardiomyopathy patients with a family history of SCD or other high risk clinical features (Class IIB)
  3. Brugada ECG abnormality or other channelopathies (e.g., Long QT Syndrome) with family history of SCD (Class IIB).

CARDIAC RESYNCHRONIZATION THERAPY

  1. Cardiac Resynchronization Therapy (Bi-Ventricular Pacing) is indicated for patients with the following characteristics:
  2. LVEF  0.35
  3. Dilated cardiomyopathy: ischemic or non-ischemic
  4. Heart failure: Class III or IV
  5. QRS duration  120 msec

Caveats:

  • CRT should not be considered as salvage therapy
  • Patients considered for CRT should be optimally medically managed first
  1. CRT plus ICD is indicated for all patients that meet the criteria for CRT pacing.
    Caveats:
  • Based on COMPANION and CARE-HF
  • CRT pacing without ICD might be considered if the ICD therapy is thought by the patient to be inconsistent with their end-of-life preferences

SELECTED REFERENCES

  1. MADIT I. NEJM 1996; 335: 1933-1940
  2. AVID. NEJM 1997; 337: 1576-1583
  3. MUSTT. NEJM 1999; 341: 1882-1890
  4. MADIT II. NEJM 2002; 346: 877-883
  5. MUSTIC. JACC 2002; 40:111-118
  6. MIRACLE. NEJM 2002; 346:1845-1853
  7. CONTAKCD. JACC 2003:42:1460-1462
  1. COMPANION. NEJM 2004; 350: 2140-2150
  2. DEFINITE. NEJM 2004; 350: 2151-2158
  3. SCD-HeFT. NEJM 2005; 352: 225-237
  4. CARE-HF. NEJM 2005; 352: 1539-1549

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